1. Field of the Invention
This invention generally relates to changing print elements in single element printers. More specifically, this invention deals with repositioning a ribbon cartridge and causing engagement and disengagement of a print element and selection motor to facilitate a print element change.
2. Description of the Prior Art
Any number of single element printers are available in the marketplace today. The most common fall into the golf ball and daisy wheel categories. Typical of the golf ball printers are those utilized in the IBM Mag Card "Selectric"* Typewriter and IBM Mag Card II Typewriter systems. The printers in both of these systems have a carrier carrying a print element which is tiltable and rotatable for printing. The basic distinction between the carriers in the above mentioned systems is that escapement in the first is rack and pawl controlled whereas in the latter escapement is pawl and leadscrew controlled. FNT *Registered Trademark-International Business Machines Corporation
The print element utilized in both of these printers is sufficiently displaced from the ribbon when the printers are in the idle or off condition to permit a print element change with little difficulty and without affecting the ribbon. Another reason the ribbon need not be displaced or removed for a print element change is the physical size of the print element relative to the unlatching mechanism located on the top thereof.
Somewhat typical of the daisy wheel printers on the market today is that used in the IBM 6240 Mag Card Typewriter system. The printer of this system has a carrier carrying a selection motor and a ribbon cartridge. The selection motor has a hub to which is connected a daisy wheel print element. The print element is rotatable for character selection during printing, and the periphery thereof is located closely adjacent the ribbon when in position for printing.
In this type of printer, a ribbon cartridge and ribbon are often located in an interfering position when a print element change is required. With this being the case, the cartridge and included ribbon must be removed from the carrier for efficiently handling a print element change. Once the ribbon has been removed, the motor must be canted or pivoted up for a change in print elements.
Other prior art related to daisy wheel printers include U.S. patent application Ser. No. 767,250 (now U.S. Pat. No. 4,127,335 to Bogert et al.), filed Feb. 10, 1977, and U.S. Pat. No. 4,124,312 to Johnson. In both of these references, a carrier is disclosed for carrying a daisy wheel print element housed in a cartridge, a ribbon cartridge, and a selection motor.
Not shown or utilized in any of the above-mentioned prior art, is apparatus for permitting a ribbon cartridge to be pivotally displaced to a non-interfering location and at the same time cause disengagement of a selection motor and print element to permit a print element change.